The invention relates to a method for fabricating a semiconductor on insulator wafer which comprises the steps of providing a semiconductor substrate or a substrate that includes an epitaxial semiconductor layer as a source substrate, attaching the source substrate to a handle substrate to form a source handle assembly and detaching a main part of the source substrate at a predetermined splitting area, provided inside the source substrate and being essentially parallel to the main surface, from the source handle assembly to thereby create the semiconductor on insulator wafer. The invention also relates to the corresponding semiconductor on insulator wafers made by this method.
In these types of structures, e.g., for germanium on insulator wafers, the interface state density between the semiconductor and the underlying insulator layer often is not good enough to achieve acceptable electric characteristics. In some cases, for example germanium on silicon dioxide, the semiconductor layer and/or the interface with the oxide deteriorates due to oxidation. To overcome this problem, it has been proposed to modify the insulating layer by using Si3N4, Ge3N4 or GexOyNz layers. However, up to now, no acceptable interfaces have been achieved. Thus, there is a need for such structures with improved interfaces and these are now provided by the present invention.